package com.feifan.dao;

import com.feifan.vo.User;

import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

public interface IUserDao {
    //接口只有定义没有实现
    public List<User> show();
    public boolean delete(int id);//id为主键
    public boolean add(User user);
    public User update(int id);
}
